This invention relates to a method and an apparatus for continuously filling grooves in metal sash bars with heat insulating material in the manufacturing of heat insulating sash bars.
It has been known that heat insulating sash bars are continuously produced by filling each groove in extruded hollow metallic sash bars with heat insulating synthetic resin. In the production of such products, after the groove in one sash bar is filled with heat insulating synthetic resin and before the groove in the succeeding sash bar is filled with heat insulating synthetic resin, the resin filling operation has to be temporally interrupted, since the two sash bars are spaced apart from each other. However, it is not easy to determine the timing for interrupting the filling operation for optimum volume and the flow rate in the starting of the next filling operation tends to vary, resulting in uneven filling. To avoid such disadvantages, there has been proposed an approach by which a tray is disposed below the filling zone to receive any excess of synthetic resin which has been poured into the space between the successive sash bars and which has not been filled into the sash bars while the synthetic resin is continuously poured and the excess resin is then discharged out of the system. However, this approach does not allow the excess resin to be reused and is, therefore, very wasteful.